Obtaining a homogeneous washing liquor during laundry cleaning process in a washing machine is a very important factor for obtaining a satisfactory end-result.
Efficient dosing and dispensing is key for ensuring that the given amount of detergent is used at its maximum capacity within the washing machine. This requirement becomes even stricter especially in cases when the detergent compositions comprise several detergent active compounds which need to interact in the washing liquor but should not interact when present in the detergent composition itself; for example, when liquid detergent compositions contain bleaching active compounds which could interact with bleach sensitive detergent ingredients such as enzymes.
There currently exist several devices suitable to be used during cleaning processes in a washing machine. Examples of such devices with a single dosing chamber include for example the devices described in US2012023678 or EP2108068, directed to dispensing a limited quantity of detergent compositions throughout a washing cycle. Another similar device is known for deodorizing linen during air drying is described in US2009300933. The outer shell of the device of US2009300933 instead of directly accommodating a cleaning solution, comprises a core made of a sponge impregnated with a deodorizing substance that is released through the openings in the shell during a drying process.
Several two-vessel-based solution are also known in the art and include for example U.S. Pat. No. 4,835,804 that discloses a device for laundry washing, comprising an outer container for retaining one detergent composition and further containing also an inner reservoir for retaining another detergent composition that is incompatible with the first detergent composition retained in the outer container. Both outer container and the inner reservoir of the device of U.S. Pat. No. 4,835,804 open directly to the outer atmosphere and release their concentrated contents onto the surrounding laundry through separate openings directly communicating with the outside of the device (i.e. unmixed). Another two-chamber device is known from KR101222784 which comprises an internal reservoir retaining a detergent composition and opening directly to outer atmosphere for the purpose of releasing said composition directly onto the laundry undergoing a wash, and an outer container surrounding the lateral sides of said inner reservoir, said outer container retaining a plurality of porous ceramic balls for emitting far-infrared radiation participating in water activation during the washing process. As in U.S. Pat. No. 4,835,804, the inner compartments of the two vessels forming the device of KR101222784 are not in direct fluid communication with one another. In contrast, U.S. Pat. No. 5,355,541 teaches a two-vessel device for a stain pre-treatment prior to washing fabrics in a washing machine, wherein the outer container retaining a liquid detergent composition does not communicate with the outer atmosphere but is in direct fluid communication with a partially container therein inner reservoir. This inner reservoir on the other hand comprises application means, such as a sponge or a wick-like element, which extends to the outer atmosphere outside the device and serves the purpose of controlled distributing of the detergent composition directly onto stains. For better understanding of how the above listed 2—vessel devices are made, FIG. 1 provides their schematic representation (A—the device of U.S. Pat. No. 4,835,804; B—the device of KR101222784; C— the device of U.S. Pat. No. 5,355,541; reference numbers refer to: 1—inner reservoir; 2—inner reservoir opening, 3—outer container; 4—outer container opening; d—detergent composition)
Unfortunately, all of the afore-listed devices fail to obtain a homogenized washing liquor capable of distributing evenly in the washing machine. Due to the difference in viscosity between water and the cleaning solution, once the detergent composition leaves the dosing device, it will substantially enter in contact with only specific items present in the washing machine and adhere to them. Since only a minimum concentration of cleaning solution will reach the rest of the items, these items will be less efficiently washed and may have to be rewashed.
Therefore it is clear from the above that there remains a need on the market for a dosing and dispensing device comprising an interspace acting as a dilution chamber which provides for a more homogenized washing liquor ensuring a more efficient laundry cleaning process.
It is another object of the present invention to provide a device suitable for dosing and dispensing detergent compositions, either granulated or liquid, in particular detergent compositions having bleach sensitive detergent active compounds.
It is a further object of the present invention to provide a device capable of controlling the dispensing of the detergent composition throughout the total duration of the cleaning process.